## Summary - align MDXEditor’s placeholder overlay with the empty document’s first writing position on wide canvases - render the placeholder with Chopin’s quaternary text token - extend the Chromium regression to cover alignment, color, and typing position

## Verification - bun test (1277 passed, 2 skipped, 0 failed) - bun run types - bun run ci - bun run e2e --grep "an empty plan puts its muted prompt at the first writing position" - production client build (run by the focused E2E command) - thermo-nuclear code-quality review: approved with no findings